\text { An LTI system has the impulse response } h(t)=u(t)-2 u(t-1)+u(t-2) \text { . } Determine whether this system is causal. Determine whether this system is stable. \text {

Find and sketch the system response } y(t) \text { to the input } x(t)=\delta(t-1)-2 \delta(t-2) \text { . }